Sound-Attenuating Muffler Having Reduced Back Pressure

ABSTRACT

A sound-attenuating muffler having a muffler housing with a volume displacement to engine displacement ratio of less than 8:1 and a width to height ratio between 1.05:1-3.5:1. The muffler also includes a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough. A deflection element is attached to an upstream side of the partition along its width and height thereby provide at least one side opening on each side along the width and at least one end opening on each end along the height for the passage of exhaust gases therethrough. A ratio of the open area of both the end openings to the open area of the partition opening is between 0.7:1-3.7:1 and a ratio of an open area of both side openings to the open area of the partition opening is between 0.3:1-3.5:1.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to sound-attenuating mufflers for use with internal combustion engines and, in particular, it concerns improvements to such sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.

Numerous muffler constructions have been proposed for the attenuation of the sound component of an exhaust gas stream from an internal combustion engine. The present invention is an improvement to the low back-pressure sound-attenuating mufflers of U.S. Pat. Nos. 6,286,623, 6,776,257, 7,708,114 and 7,708,115 to the present inventor and incorporated herein by reference.

As new automobiles become smaller in size, the components used to build such vehicles need to be smaller. The current technology in the art of automobile mufflers provides for mufflers having a muffler housing volume displacement to engine displacement ratio of greater than 8:1, and generally in the range of 8:1-15:1. For a 2 L engine, for example, the muffler could be as large as 30 L, which is too large for some models of small sporty automobiles with powerful engines.

It must be noted, however, that the aspects of exhaust noise level, muffler size and exhaust back pressure are so related that reducing one or more aspects may adversely affect the other aspects. That is to say, generally, reducing the size of the muffler tends to increase the noise level. However, reducing both the size of the muffler and adding elements in order to maintain the noise reduction level generally results in an increase in back pressure. As noted in the prior art, increased back pressure adversely affects fuel economy and overall engine performance.

Larger size also involves greater weight and material costs.

There is therefore a need for sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.

SUMMARY OF THE INVENTION

The present invention relates to sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.

According to the teachings of the present invention there is provided, a sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; (b) the muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1; (c) a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough; and (d) a deflection element deployed in the muffler housing and attached to an upstream side of the partition, the deflection element having a width, height and length such that the attached to the partition is along its width and height so as to provide at least one side opening on each side along the width and at least one end opening on each end along the height for the passage of exhaust gases therethrough, such that a ratio of an open area of both the end openings to an open area of the partition opening is in a range of 0.7:1-3.7:1 and a ratio of an open area of both the side openings to the open area of the partition opening is in a range of 0.3:1-3.5:1.

According to a further teaching of the present invention, the deflection element is a hollow pyramid configured with: (a) a side-view apex angle measuring between 70°-179°; (b) an end-view apex angle measuring between 35°-115°; (c) a side-view shoulder angle measuring between 89°-180°; (d) an end-view shoulder angle measuring between 110°-180°; (e) a side opening apex angle measuring between 90°-180°; and the partition is configured with a base section and sloping end sections to which the deflection element is attached such that an angle of the sloping sections to the base section measures between 83°-180°.

According to a further teaching of the present invention, (a) the side-view apex angle is 122°; (b) the end-view apex angle is 65°; (c) the side-view shoulder angle is 155°; (d) the end-view shoulder angle is 155°; (e) the side opening apex angle is 105°; and (f) the angle of the sloping sections to the base section is 135°.

According to a further teaching of the present invention, the muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.

According to a further teaching of the present invention, the muffler housing width to height ratio is 1.8:1.

According to a further teaching of the present invention, the ratio of the open area of both the end openings to the open area of the partition opening is 1.8:1 and the ratio of the open area of both the side openings to the open area of the partition opening is 0.9:1.

There is also provided according to the teachings of the present invention, a sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough, the partition configured with a base section and sloping end sections such that an angle of the sloping sections to the base section measures between 83°-180°; and (b) a deflection element deployed in the muffler housing and attached to an upstream side of the partition, the deflection element is a hollow pyramid having: (i) a side-view apex angle measuring between 70°-179°; (ii) an end-view apex angle measuring between 35°-115°; (iii) a side-view shoulder angle measuring between 89°-180°; (iv) an end-view shoulder angle measuring between 110°-180°; and (v) a side opening apex angle measuring between 90°-180°.

According to a further teaching of the present invention, (a) the angle of the sloping sections to the base section is 135°; (b) the side-view apex angle is 122°; (e) the end-view apex angle is 65°; (d) the side-view shoulder angle is 155°; (e) the end-view shoulder angle is 155°; and (f) the side opening apex angle is 105°.

According to a further teaching of the present invention, there is also provided (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; and (b) the muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1.

According to a further teaching of the present invention, the muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.

There is also provided according to the teachings of the present invention, a sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a muffler housing having a width to height ratio in a range of 1.05:1-3.5:1; and (b) a deflection element deployed in the muffler housing, the deflection element being configured as a hollow pyramid having: (i) a side-view apex angle measuring between 70°-179°; (ii) an end-view apex angle measuring between 35°-115°; (iii) a side-view shoulder angle measuring between 89°-180°; (iv) an end-view shoulder angle measuring between 110°-180°; and (v) a side opening apex angle measuring between 90′-180°.

According to a further teaching of the present invention, the muffler housing has a volume displacement to engine displacement ratio of less than 8:1.

According to a further teaching of the present invention, muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.

According to a further teaching of the present invention, the muffler housing width to height ratio is 1.8:1.

According to a further teaching of the present invention, there is also provided (a) a partition configured to divide the muffler housing into separate compartments, the partition also having a partition opening for the passage of exhaust gases therethrough, the partition configured with a base section and sloping end sections such that an angle of the sloping sections to the base section measures between 83°-180°; and (b) the hollow pyramid is attached to an upstream side of the partition, the hollow pyramid having: (i) the angle of the sloping sections to the base section is 135°; (ii) the side-view apex angle is 122°; (iii) the end-view apex angle is 65°; (iv) the side-view shoulder angle is 155°; (v) the end-view shoulder angle is 155°; and (vi) the side opening apex angle is 105°.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein the terms “top”, “bottom”, “side” and “end” refer to the position of the components of the present invention with respect to their position in a muffler when installed in a vehicle and as shown in FIG. 1, wherein:

FIG. 1 is a perspective, cut-open view of the muffler of FIG. 1 of U.S. Pat. No. 7,708,114;

FIG. 2 is an upstream end view of the partition and deflection element assembly of FIG. 3;

FIG. 3 is a top section of the partition and deflection element assembly of FIG. 3 taken along the median of the width of the deflection element;

FIG. 4 is a side section of the partition and deflection element assembly of FIG. 3 taken on line B-B of FIG. 4;

FIG. 5 is a downstream view of the partition and deflection element assembly of FIG. 3; and

FIG. 6 is a schematic representation of the range of the muffler housing width to height ratios according to the teaching of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to sound-attenuating mufflers allowing for a reduction in the overall size of the muffler while maintaining reduced back pressure.

The principles and operation of sound-attenuating mufflers according to the present invention may be better understood with reference to the drawings and the accompanying description.

By way of introduction, as mentioned above the current automobile muffler technology requires a muffler housing volume displacement to engine displacement ratio of greater than 8:1, and generally in the range of 8:1-15:1. It should be understood that the combination of improvements disclosed herein result in the ability to meet the same level of noise suppression with a muffler housing volume displacement to engine displacement ratio of less than 8:1, and generally in the range of 4:1-7.9:1. Such a smaller size represents a drastic reduction in size, weight and cost of materials over the current state of the art. However, as noted above and in U.S. Pat. Nos. 6,286,623, 6,776,257, 7,708,114 and 7,708,115 to the present inventor and incorporated herein in their entirety as if fully recited, the design of the muffler of the present invention maintains a reduced back pressure load. Thereby enabling the muffler of the present invention to reduce all three aspects addressed by vehicle muffler, specifically, the aspects of exhaust noise level, muffler size and exhaust back pressure to size/level combinations unattainable in the prior art.

Specifically, these improvements relate to the muffler housing width to height ratio, the shape of the deflection element and the relationship of the partition and deflection element, as will be discussed in more detail below.

It should be understood that the terms width, height and length are used herein, and especially in the claims, to refer to the relative position of the elements of the present invention as they would be oriented in a muffler when installed on an automobile and/or as illustrated in FIG. 1.

Referring now to the drawings, FIG. 1 is presented here in order to illustrate the deployment of the partition and deflection element assembly 2 of the present invention within a muffler housing 300. It will be readily understood from this drawing that the deflection element 100 is attached to the partition 20 on the upstream side of partition 20.

As illustrated in FIG. 2, partition element 200 is configured with an outlet opening 202. As is disclosed at length in U.S. Pat. Nos. 6,286,623, 6,776,257, 7,708,114 and 7,708,115 mentioned above, exhaust gases flow over the hollow pyramid shaped deflection element 100, through the two side openings 102 and two end openings 104 and through the partition opening 202. Both side openings 102 and both end openings 104 are clearly visible here.

Although the concept of a hollow pyramid shaped deflection element 100 was disclosed in the patents listed above to the present inventor, the inventor has developed improvements in the shape of the hollow pyramid 100, the partition 200 and the relationship/interconnection of the two as will now be explained.

FIG. 3 is an illustrative side section taken along the median of the width of the hollow pyramid 100, showing the side walls of the muffler housing 300, the hollow pyramid 100 and the partition 200. FIG. 6 is an illustrative end section of the hollow pyramid 100, showing the height 150 and length 160 of the hollow pyramid 100. As a reference point, the apex 108 of the hollow pyramid 100 is labeled. Among the improvements to the hollow pyramid 100 are certain angles that affect the manner in which the exhaust gases flow over the hollow pyramid shaped deflection element 100, through the side openings 102 and end openings 104 and through the partition opening 202.

Specifically, the side-view apex angle 110 may measure between 70°-179°, but the preferred angle is 122°. The end-view apex angle 112 may measure between 35°-115°, but the preferred angle is 65°. The side-view shoulder angle 120 may measure between 89°-180°, but the preferred angle is 155°. The end-view shoulder angle 122 may measure between 110°-180°, but the preferred angle is 155°. The side opening apex angle 130 may measure between 90°-180°, but the preferred angle is 105°.

As illustrated, the partition 200 may optionally, or preferably, be configured with a base section 210 and sloping end sections 220 to which the hollow pyramid deflection element 100 is attached. The angle 222 of the sloping sections 220 to the base section 210 may measure between 83°-180°, but the preferred angle is 135°.

Regarding the relationship between the hollow pyramid 100 and the partition 200, referring back to FIG. 2, the ratio of an open area of both of the end openings 104 combined to the open area of the partition opening 202 is in a range of 0.7:1-3.7, with a preferred angle of 1.8:1. The ratio of the open area of both said side openings 102 combined to the open area of the partition opening 202 is in a range of 0.3:1-3.5:1, with a preferred angle of 0.9:1.

Regarding the muffler housing width 170 to height 150 ratio, FIG. 5 illustrates a preferred configuration showing a ratio of 1.8:1. FIG. 6 illustrates an operational range of the muffler housing width 170 to height 150 ratio, wherein width is illustrated as a constant and, height 150′ illustrates a ratio of 1.05:1, height 150″ illustrates a ratio of 3.5:1 and height 150 illustrates the preferred ratio of 1.8:1 as a reference example. While FIG. 6 illustrates an operational range of the muffler housing width 170 to height 150 ratio by changing only the height, it will be appreciated that substantially any variation, or combination, of height, width or both that results in a height to width ratio within the range of 1.05:1 to 3.5:1 is considered within the scope of the present invention.

It will be appreciated that while any of the improvements described herein may be used individually to benefit in the construction of a sound-attenuating muffler for use with an internal combustion engine, the synergy of the combination of the preferred angles, ratios and relationships of the improvements of the present invention enable the production of muffler having a housing with a volume displacement to engine displacement ratio of less than 8:1, and even in the range of 5:1-6:1, which until now was considered unattainable.

It will be appreciated that the above descriptions are intended only to serve as examples and that many other embodiments are possible within the spirit and the scope of the present invention. 

What is claimed is:
 1. A sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; (b) said muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1; (c) a partition configured to divide said muffler housing into separate compartments, said partition also having a partition opening for the passage of exhaust gases therethrough; and (d) a deflection element deployed in said muffler housing and attached to an upstream side of said partition, said deflection element having a width, height and length such that said attached to said partition is along its width and height so as to provide at least one side opening on each side along said width and at least one end opening on each end along said height for the passage of exhaust gases therethrough, such that a ratio of an open area of both said end openings to an open area of said partition opening is in a range of 0.7:1-3.7:1 and a ratio of an open area of both said side openings to said open area of said partition opening is in a range of 0.3:1-3.5:1.
 2. The sound-attenuating muffler of claim 1, wherein said deflection element is a hollow pyramid configured with: (a) a side-view apex angle measuring between 70°-179°; (b) an end-view apex angle measuring between 35°-115°; (c) a side-view shoulder angle measuring between 89-180°; (d) an end-view shoulder angle measuring between 110-180°; (e) a side opening apex angle measuring between 90°-180°; and said partition is configured with a base section and sloping end sections to which said deflection element is attached such that an angle of said sloping sections to said base section measures between 83°-180°.
 3. The sound-attenuating muffler of claim 2, wherein (a) said side-view apex angle is 122°; (b) said end-view apex angle is 65°; (c) said side-view shoulder angle is 155°; (d) said end-view shoulder angle is 155°; (e) said side opening apex angle is 105°; and (f) said angle of said sloping sections to said base section is 135°.
 4. The sound-attenuating muffler of claim 1, wherein said muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.
 5. The sound-attenuating muffler of claim 1, wherein said muffler housing width to height ratio is 1.8:1.
 6. The sound-attenuating muffler of claim 1, wherein said ratio of said open area of both said end openings to said open area of said partition opening is 1.8:1 and said ratio of said open area of both said side openings to said open area of said partition opening is 0.9:1.
 7. A sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a partition configured to divide said muffler housing into separate compartments, said partition also having a partition opening for the passage of exhaust gases therethrough, said partition configured with a base section and sloping end sections such that an angle of said sloping sections to said base section measures between 83°-180°; and (b) a deflection element deployed in said muffler housing and attached to an upstream side of said partition, said deflection element is a hollow pyramid having: (i) a side-view apex angle measuring between 70°-179°; (ii) an end-view apex angle measuring between 35°-115°; (iii) a side-view shoulder angle measuring between 89°-180°; (iv) an end-view shoulder angle measuring between 110°-180°; and (v) a side opening apex angle measuring between 90°-180°.
 8. The sound-attenuating muffler of claim 7, wherein (a) said angle of said sloping sections to said base section is 135°; (b) said side-view apex angle is 122°; (c) said end-view apex angle is 65°; (d) said side-view shoulder angle is 155°; (e) said end-view shoulder angle is 155°; and (f) said side opening apex angle is 105°.
 9. The sound-attenuating muffler of claim 7, further including: (a) a muffler housing having a volume displacement to engine displacement ratio of less than 8:1; and (b) said muffler housing also having a width to height ratio in a range of 1.05:1-3.5:1.
 10. The sound-attenuating muffler of claim 9, wherein said muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.
 11. A sound-attenuating muffler for use with an internal combustion engine, the sound-attenuating muffler comprising: (a) a muffler housing having a width to height ratio in a range of 1.05:1-3.5:1; and (b) a deflection element deployed in said muffler housing, said deflection element being configured as a hollow pyramid having: (i) a side-view apex angle measuring between 70°-179°; (ii) an end-view apex angle measuring between 35°-115°; (iii) a side-view shoulder angle measuring between 89°-180°; (iv) an end-view shoulder angle measuring between 110°-180°; and (v) a side opening apex angle measuring between 90°-180°.
 12. The sound-attenuating muffler of claim 11, wherein said muffler housing has a volume displacement to engine displacement ratio of less than 8:1.
 13. The sound-attenuating muffler of claim 12, wherein muffler housing volume displacement to engine displacement ratio is in a range of 5:1-6:1.
 14. The sound-attenuating muffler of claim 11, wherein said muffler housing width to height ratio is 1.8:1.
 15. The sound-attenuating muffler of claim 11, further including: (a) a partition configured to divide said muffler housing into separate compartments, said partition also having a partition opening for the passage of exhaust gases therethrough, said partition configured with a base section and sloping end sections such that an angle of said sloping sections to said base section measures between 83°-180°; and (b) said hollow pyramid is attached to an upstream side of said partition, said hollow pyramid having: (i) said angle of said sloping sections to said base section is 135°; (ii) said side-view apex angle is 122°; (iii) said end-view apex angle is 65°; (iv) said side-view shoulder angle is 155°; (v) said end-view shoulder angle is 155°; and (vi) said side opening apex angle is 105°. 